LEGUMINOS^. 



83 



Subtribe 3. Tkifolie^. 

 172. MEDICAGO. 



Tie points of comparison taken by different 

 authors in determining the species of this genus 

 are so various, and expressed in such different 

 terms, that I find it impossible to reduce them 

 satisfactorily to an analytical fonn. I, how- 

 ever, publish the following attempt at grouping, 

 as the best I have been able to effect ; thinking 

 it may be useful to the student, though I feel 

 uncertain as to the constancy of some of the 

 chai'acters, and am aware that some of them 

 so run into others, that he may be puzzled as 

 to which he ought to choose. 



I have described the spines with reference 

 to the helix, and not to the legume in its 

 lengthened form. Adpressed, if tm-ned up and 

 down, close to the helix ; reflexed, tm-ned also 

 up and down, but not lying close against the 

 turns of the helix ; (both these appear to be 

 sometimes called divaricate ;) spreading, when 

 they are more open ; radiating , when, they near- 

 ly follow the direction of the width of the legume 



A. Legume somewhat leaf-Uke, reniform 

 Sp. 1, 2. 



B. Legume curved, solid, open in the centre 

 Sp. 3-8. 



C. Legume renifoi-m, not open in centre, 

 longitudinally veined. Sp. 9, 10. 



D. Legume spiral, closed. Edge thin, un 

 armed. Sp. 11-17. 



E. Legume spiral, closed. Edge thickened 

 1 -nerved, unarmed, or only slightly tu 

 bercled. Sp. 18-22. 



P. Legimie spiral. Outer sutm-e S-nei-ved 

 unanned, or only slightly tubercled. Sp 

 23-26. 



G. Legume spiral, closed. Outer suture 3- 

 nerved, armed with spines that are not 

 grooved. 

 i. Edges touching. Sp. 27-30. 

 ii. Edges not touching. Sp. 31-36. 

 H. Legume spiral. Spines grooved. 

 i. Back keeled. Sp. 37. 



ii. Back rounded. Base of Spines extending 

 to the centre. 



a. Legumenotveinedonmaxgin. Sp. 38-40. 



b. Legume veined all over. Sp. 41-46. 



iii. Back flattened, not occupied by the 

 spines. Sp. 47-49. 



I. Back 1 -nerved. Sjnnes grooved, arising 

 from the back and from a lateral vein. 



i. HeUx trencher-shaped. Sp. 50. 

 ii. HeHx ellipsoid or subglohose. 



51-55. 



Sp. 



A. Legume somewhat leaf-like, compressed, 



reniform. 



1. circinnata. Margin of Leg. not winged, 

 but fui-uished with branched, spine-like teeth. 

 Lts. 5, entii-e; terminal very large, a. 3, 4. 

 Brg hills. It. s. Er. 



2. radiata. Margin of Leg. winged, dentate. 

 Lts. 3, obovato-denticulate. a. 6, 7. Nice. 

 Narbonne. Koch says, " Anterior margin spi- 

 nulose, posterior with a ragged fringe," and 

 makes no mention of a wing. Query, if the 

 same plant . a. 7, 8. Fields. Istria. 



B. Legume curved, solid, open in the centre. 



3. procumbens. Prociunbent. Leg. nearly 

 straight, reticulate. Seeds 2-6, irregularly 

 cordate. Lts. oblongo -linear, dentate at top. 

 Stip. dentate at base. p. 7-9. Bry hills. Boh. 

 Dresd. [Far. (T/falcata, Koch.) 



4. falcata. Decumbent. Leg. sickle-shaped, 



reticulate. Lts. oblong. Stip. subulate, quite 

 entire. Kac. short, erect. Pedicels shorter 

 than calyx, erect after flowering, p. 6, 7- L)ry 

 meadows and banks. 



5. arborea. Shrub erect, silky. Leg. an- 

 nular. Seeds 2, 3. Lts. obovate. Stip. subulate, 

 entire. S. 4, 5. Nice. Sorrento. 



6. ^lutinosa. Prosti'ate. Hairs viscid. 

 Leg. (annular, Rchb.,) obscurely veined. Lts. 

 obovato-cuneiform, somewhat refuse, obscm'ely 

 dentate. Stip. lanceolate, somewhat dentate at 

 base. (Rac. corymbose, Rchb.) p. 5, 6. Stony 

 meadows. Mte.Spaccato. Trieste. Not in Koch. 



7. sativa. Erect. Leg. somewhat spiral, 

 finely reticulate, silky when young. Stalk 

 shorter than calyx. Seeds irregular, bay. Lts. 

 obovato-oblong, dentate. Stip. subulate, some- 

 what dentate. Rac. oblong, erect, p. 6, 7- 

 Meadows and borders. 



8. prostrata. Prostrate. Leg. somewhat 

 spiral, finely reticulate. Seeds 2, exactly reni- 

 form, black. Pedicels twice calyx, refracted 

 after flowering. - Lts. Knear. Stip. Kneari-siibu- 

 late, nerved, dentate at base. p. 6-8. Open 

 uncult. Tiieste. abundant. Cam. 



C. Legume reniform, thick, not open in the 



centre. 



9. lupulina. Procumbent. Leg. reniform, 

 1 -seeded, lougitudinaUy veined. Lts. obovato- 

 cuneate, obtusely dentate. Stip. subulate, nearly 



M 2 



